Question: Calculating Surface Area of Prisms and Pyramids Using Nets
What is the surface area of the given triangular prism with an isosceles base?
In the triangular prism:
BC = 6 ft
AD = 5 ft
FH = 5.83 ft
CH = 9 ft
Use the given information to complete the worksheet.
Let's figure out a solution plan.
How many shapes of different dimensions make up the net of this figure? 3
Shape Legend
Base Length (ft)
Height Length (ft)
Area of a Single Shape (ft²)
How Many of This Shape
Total Area of These Shapes (ft²)
Triangle
Rectangle
Rectangle
The surface area of the triangular prism with an isosceles base is
1. **State the problem:** We need to find the surface area of a triangular prism with an isosceles triangular base.
2. **Identify the shapes in the net:** The net consists of 3 rectangles and 2 congruent triangles.
3. **Given dimensions:**
- Base of triangle (BC) = $6$ ft
- Height of triangle (AD) = $5$ ft
- Slant height of triangle side (FH) = $5.83$ ft
- Length of prism (CH) = $9$ ft
4. **Calculate the area of one triangle:**
$$\text{Area}_{\triangle} = \frac{1}{2} \times \text{base} \times \text{height} = \frac{1}{2} \times 6 \times 5 = 15 \text{ ft}^2$$
5. **Calculate the area of the rectangles:**
- Rectangle 1 (base rectangle): length $6$ ft, height $9$ ft
$$\text{Area}_{R1} = 6 \times 9 = 54 \text{ ft}^2$$
- Rectangle 2 (side rectangle): length $5$ ft, height $9$ ft
$$\text{Area}_{R2} = 5 \times 9 = 45 \text{ ft}^2$$
- Rectangle 3 (slant side rectangle): length $5.83$ ft, height $9$ ft
$$\text{Area}_{R3} = 5.83 \times 9 = 52.47 \text{ ft}^2$$
6. **Calculate total area of triangles:**
There are 2 congruent triangles:
$$2 \times 15 = 30 \text{ ft}^2$$
7. **Calculate total area of rectangles:**
$$54 + 45 + 52.47 = 151.47 \text{ ft}^2$$
8. **Calculate total surface area:**
$$\text{Surface Area} = \text{Area of triangles} + \text{Area of rectangles} = 30 + 151.47 = 181.47 \text{ ft}^2$$
**Final answer:** The surface area of the triangular prism is approximately $181.47$ square feet.